Commit | Line | Data |
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d58d1454 MD |
1 | /* |
2 | * lttng-context-perf-counters.c | |
3 | * | |
4 | * LTTng UST performance monitoring counters (perf-counters) integration. | |
5 | * | |
6 | * Copyright (C) 2009-2014 Mathieu Desnoyers <mathieu.desnoyers@efficios.com> | |
7 | * | |
8 | * This library is free software; you can redistribute it and/or | |
9 | * modify it under the terms of the GNU Lesser General Public | |
10 | * License as published by the Free Software Foundation; only | |
11 | * version 2.1 of the License. | |
12 | * | |
13 | * This library is distributed in the hope that it will be useful, | |
14 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
16 | * Lesser General Public License for more details. | |
17 | * | |
18 | * You should have received a copy of the GNU Lesser General Public | |
19 | * License along with this library; if not, write to the Free Software | |
20 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA | |
21 | */ | |
22 | ||
3fbec7dc | 23 | #define _LGPL_SOURCE |
d58d1454 MD |
24 | #include <sys/types.h> |
25 | #include <unistd.h> | |
26 | #include <string.h> | |
27 | #include <stdlib.h> | |
28 | #include <stdio.h> | |
649fb6b3 | 29 | #include <stdbool.h> |
d58d1454 MD |
30 | #include <sys/mman.h> |
31 | #include <sys/syscall.h> | |
d58d1454 MD |
32 | #include <lttng/ust-events.h> |
33 | #include <lttng/ust-tracer.h> | |
34 | #include <lttng/ringbuffer-config.h> | |
595c1577 | 35 | #include <lttng/ust-cancelstate.h> |
d58d1454 MD |
36 | #include <urcu/system.h> |
37 | #include <urcu/arch.h> | |
38 | #include <urcu/rculist.h> | |
39 | #include <helper.h> | |
40 | #include <urcu/ref.h> | |
41 | #include <usterr-signal-safe.h> | |
42 | #include <signal.h> | |
20142124 | 43 | #include <urcu/tls-compat.h> |
77d7fa98 | 44 | #include "perf_event.h" |
d58d1454 MD |
45 | #include "lttng-tracer-core.h" |
46 | ||
47 | /* | |
48 | * We use a global perf counter key and iterate on per-thread RCU lists | |
49 | * of fields in the fast path, even though this is not strictly speaking | |
50 | * what would provide the best fast-path complexity, to ensure teardown | |
51 | * of sessions vs thread exit is handled racelessly. | |
52 | * | |
53 | * Updates and traversals of thread_list are protected by UST lock. | |
54 | * Updates to rcu_field_list are protected by UST lock. | |
55 | */ | |
56 | ||
57 | struct lttng_perf_counter_thread_field { | |
58 | struct lttng_perf_counter_field *field; /* Back reference */ | |
59 | struct perf_event_mmap_page *pc; | |
60 | struct cds_list_head thread_field_node; /* Per-field list of thread fields (node) */ | |
61 | struct cds_list_head rcu_field_node; /* RCU per-thread list of fields (node) */ | |
b9389e6e | 62 | int fd; /* Perf FD */ |
d58d1454 MD |
63 | }; |
64 | ||
65 | struct lttng_perf_counter_thread { | |
66 | struct cds_list_head rcu_field_list; /* RCU per-thread list of fields */ | |
67 | }; | |
68 | ||
69 | struct lttng_perf_counter_field { | |
70 | struct perf_event_attr attr; | |
71 | struct cds_list_head thread_field_list; /* Per-field list of thread fields */ | |
72 | }; | |
73 | ||
74 | static pthread_key_t perf_counter_key; | |
75 | ||
20142124 MD |
76 | /* |
77 | * lttng_perf_lock - Protect lttng-ust perf counter data structures | |
78 | * | |
79 | * Nests within the ust_lock, and therefore within the libc dl lock. | |
80 | * Therefore, we need to fixup the TLS before nesting into this lock. | |
81 | * Nests inside RCU bp read-side lock. Protects against concurrent | |
82 | * fork. | |
83 | */ | |
84 | static pthread_mutex_t ust_perf_mutex = PTHREAD_MUTEX_INITIALIZER; | |
85 | ||
20142124 MD |
86 | /* |
87 | * Track whether we are tracing from a signal handler nested on an | |
88 | * application thread. | |
89 | */ | |
90 | static DEFINE_URCU_TLS(int, ust_perf_mutex_nest); | |
91 | ||
92 | /* | |
93 | * Force a read (imply TLS fixup for dlopen) of TLS variables. | |
94 | */ | |
95 | void lttng_ust_fixup_perf_counter_tls(void) | |
96 | { | |
97 | asm volatile ("" : : "m" (URCU_TLS(ust_perf_mutex_nest))); | |
98 | } | |
99 | ||
100 | void lttng_perf_lock(void) | |
101 | { | |
102 | sigset_t sig_all_blocked, orig_mask; | |
595c1577 | 103 | int ret; |
20142124 | 104 | |
595c1577 MD |
105 | if (lttng_ust_cancelstate_disable_push()) { |
106 | ERR("lttng_ust_cancelstate_disable_push"); | |
20142124 MD |
107 | } |
108 | sigfillset(&sig_all_blocked); | |
109 | ret = pthread_sigmask(SIG_SETMASK, &sig_all_blocked, &orig_mask); | |
110 | if (ret) { | |
111 | ERR("pthread_sigmask: %s", strerror(ret)); | |
112 | } | |
113 | if (!URCU_TLS(ust_perf_mutex_nest)++) { | |
114 | /* | |
115 | * Ensure the compiler don't move the store after the close() | |
116 | * call in case close() would be marked as leaf. | |
117 | */ | |
118 | cmm_barrier(); | |
119 | pthread_mutex_lock(&ust_perf_mutex); | |
20142124 MD |
120 | } |
121 | ret = pthread_sigmask(SIG_SETMASK, &orig_mask, NULL); | |
122 | if (ret) { | |
123 | ERR("pthread_sigmask: %s", strerror(ret)); | |
124 | } | |
125 | } | |
126 | ||
127 | void lttng_perf_unlock(void) | |
128 | { | |
129 | sigset_t sig_all_blocked, orig_mask; | |
595c1577 | 130 | int ret; |
20142124 MD |
131 | |
132 | sigfillset(&sig_all_blocked); | |
133 | ret = pthread_sigmask(SIG_SETMASK, &sig_all_blocked, &orig_mask); | |
134 | if (ret) { | |
135 | ERR("pthread_sigmask: %s", strerror(ret)); | |
136 | } | |
137 | /* | |
138 | * Ensure the compiler don't move the store before the close() | |
139 | * call, in case close() would be marked as leaf. | |
140 | */ | |
141 | cmm_barrier(); | |
142 | if (!--URCU_TLS(ust_perf_mutex_nest)) { | |
20142124 MD |
143 | pthread_mutex_unlock(&ust_perf_mutex); |
144 | } | |
145 | ret = pthread_sigmask(SIG_SETMASK, &orig_mask, NULL); | |
146 | if (ret) { | |
147 | ERR("pthread_sigmask: %s", strerror(ret)); | |
148 | } | |
595c1577 MD |
149 | if (lttng_ust_cancelstate_disable_pop()) { |
150 | ERR("lttng_ust_cancelstate_disable_pop"); | |
20142124 MD |
151 | } |
152 | } | |
153 | ||
d58d1454 | 154 | static |
53569322 | 155 | size_t perf_counter_get_size(struct lttng_ctx_field *field, size_t offset) |
d58d1454 MD |
156 | { |
157 | size_t size = 0; | |
158 | ||
159 | size += lib_ring_buffer_align(offset, lttng_alignof(uint64_t)); | |
160 | size += sizeof(uint64_t); | |
161 | return size; | |
162 | } | |
163 | ||
a3a8d943 MD |
164 | static |
165 | uint64_t read_perf_counter_syscall( | |
166 | struct lttng_perf_counter_thread_field *thread_field) | |
167 | { | |
168 | uint64_t count; | |
169 | ||
170 | if (caa_unlikely(thread_field->fd < 0)) | |
171 | return 0; | |
172 | ||
173 | if (caa_unlikely(read(thread_field->fd, &count, sizeof(count)) | |
174 | < sizeof(count))) | |
175 | return 0; | |
176 | ||
177 | return count; | |
178 | } | |
179 | ||
d58d1454 MD |
180 | #if defined(__x86_64__) || defined(__i386__) |
181 | ||
182 | static | |
183 | uint64_t rdpmc(unsigned int counter) | |
184 | { | |
185 | unsigned int low, high; | |
186 | ||
187 | asm volatile("rdpmc" : "=a" (low), "=d" (high) : "c" (counter)); | |
188 | ||
189 | return low | ((uint64_t) high) << 32; | |
190 | } | |
191 | ||
77d7fa98 MD |
192 | static |
193 | bool has_rdpmc(struct perf_event_mmap_page *pc) | |
194 | { | |
195 | if (caa_unlikely(!pc->cap_bit0_is_deprecated)) | |
196 | return false; | |
197 | /* Since Linux kernel 3.12. */ | |
198 | return pc->cap_user_rdpmc; | |
199 | } | |
200 | ||
d58d1454 | 201 | static |
a3a8d943 | 202 | uint64_t arch_read_perf_counter( |
d286ad50 | 203 | struct lttng_perf_counter_thread_field *thread_field) |
d58d1454 MD |
204 | { |
205 | uint32_t seq, idx; | |
206 | uint64_t count; | |
d286ad50 | 207 | struct perf_event_mmap_page *pc = thread_field->pc; |
d58d1454 MD |
208 | |
209 | if (caa_unlikely(!pc)) | |
210 | return 0; | |
211 | ||
212 | do { | |
213 | seq = CMM_LOAD_SHARED(pc->lock); | |
214 | cmm_barrier(); | |
215 | ||
216 | idx = pc->index; | |
77d7fa98 | 217 | if (caa_likely(has_rdpmc(pc) && idx)) { |
4f58f54f MD |
218 | int64_t pmcval; |
219 | ||
220 | pmcval = rdpmc(idx - 1); | |
221 | /* Sign-extend the pmc register result. */ | |
222 | pmcval <<= 64 - pc->pmc_width; | |
223 | pmcval >>= 64 - pc->pmc_width; | |
224 | count = pc->offset + pmcval; | |
225 | } else { | |
a3a8d943 MD |
226 | /* Fall-back on system call if rdpmc cannot be used. */ |
227 | return read_perf_counter_syscall(thread_field); | |
4f58f54f | 228 | } |
d58d1454 MD |
229 | cmm_barrier(); |
230 | } while (CMM_LOAD_SHARED(pc->lock) != seq); | |
231 | ||
232 | return count; | |
233 | } | |
234 | ||
d286ad50 | 235 | static |
a3a8d943 | 236 | int arch_perf_keep_fd(struct lttng_perf_counter_thread_field *thread_field) |
d286ad50 | 237 | { |
a3a8d943 | 238 | struct perf_event_mmap_page *pc = thread_field->pc; |
d286ad50 | 239 | |
a3a8d943 | 240 | if (!pc) |
d286ad50 | 241 | return 0; |
77d7fa98 | 242 | return !has_rdpmc(pc); |
a3a8d943 | 243 | } |
d286ad50 | 244 | |
a3a8d943 | 245 | #else |
d286ad50 | 246 | |
a3a8d943 MD |
247 | /* Generic (slow) implementation using a read system call. */ |
248 | static | |
249 | uint64_t arch_read_perf_counter( | |
250 | struct lttng_perf_counter_thread_field *thread_field) | |
251 | { | |
252 | return read_perf_counter_syscall(thread_field); | |
d286ad50 JD |
253 | } |
254 | ||
a3a8d943 MD |
255 | static |
256 | int arch_perf_keep_fd(struct lttng_perf_counter_thread_field *thread_field) | |
257 | { | |
258 | return 1; | |
259 | } | |
d286ad50 | 260 | |
a3a8d943 | 261 | #endif |
d286ad50 | 262 | |
d58d1454 MD |
263 | static |
264 | int sys_perf_event_open(struct perf_event_attr *attr, | |
265 | pid_t pid, int cpu, int group_fd, | |
266 | unsigned long flags) | |
267 | { | |
268 | return syscall(SYS_perf_event_open, attr, pid, cpu, | |
269 | group_fd, flags); | |
270 | } | |
271 | ||
272 | static | |
b9389e6e | 273 | int open_perf_fd(struct perf_event_attr *attr) |
d58d1454 | 274 | { |
b9389e6e | 275 | int fd; |
d58d1454 MD |
276 | |
277 | fd = sys_perf_event_open(attr, 0, -1, -1, 0); | |
278 | if (fd < 0) | |
b9389e6e JD |
279 | return -1; |
280 | ||
281 | return fd; | |
282 | } | |
283 | ||
d286ad50 JD |
284 | static |
285 | void close_perf_fd(int fd) | |
286 | { | |
287 | int ret; | |
288 | ||
289 | if (fd < 0) | |
290 | return; | |
291 | ||
292 | ret = close(fd); | |
293 | if (ret) { | |
294 | perror("Error closing LTTng-UST perf memory mapping FD"); | |
295 | } | |
296 | } | |
297 | ||
77d7fa98 | 298 | static void setup_perf(struct lttng_perf_counter_thread_field *thread_field) |
b9389e6e JD |
299 | { |
300 | void *perf_addr; | |
d58d1454 MD |
301 | |
302 | perf_addr = mmap(NULL, sizeof(struct perf_event_mmap_page), | |
b9389e6e | 303 | PROT_READ, MAP_SHARED, thread_field->fd, 0); |
d58d1454 | 304 | if (perf_addr == MAP_FAILED) |
b9389e6e | 305 | perf_addr = NULL; |
77d7fa98 | 306 | thread_field->pc = perf_addr; |
b9389e6e | 307 | |
a3a8d943 | 308 | if (!arch_perf_keep_fd(thread_field)) { |
b9389e6e JD |
309 | close_perf_fd(thread_field->fd); |
310 | thread_field->fd = -1; | |
6c2125af | 311 | } |
d58d1454 MD |
312 | } |
313 | ||
314 | static | |
315 | void unmap_perf_page(struct perf_event_mmap_page *pc) | |
316 | { | |
317 | int ret; | |
318 | ||
319 | if (!pc) | |
320 | return; | |
321 | ret = munmap(pc, sizeof(struct perf_event_mmap_page)); | |
322 | if (ret < 0) { | |
323 | PERROR("Error in munmap"); | |
324 | abort(); | |
325 | } | |
326 | } | |
327 | ||
328 | static | |
329 | struct lttng_perf_counter_thread *alloc_perf_counter_thread(void) | |
330 | { | |
331 | struct lttng_perf_counter_thread *perf_thread; | |
332 | sigset_t newmask, oldmask; | |
333 | int ret; | |
334 | ||
335 | ret = sigfillset(&newmask); | |
336 | if (ret) | |
337 | abort(); | |
338 | ret = pthread_sigmask(SIG_BLOCK, &newmask, &oldmask); | |
339 | if (ret) | |
340 | abort(); | |
341 | /* Check again with signals disabled */ | |
342 | perf_thread = pthread_getspecific(perf_counter_key); | |
343 | if (perf_thread) | |
344 | goto skip; | |
345 | perf_thread = zmalloc(sizeof(*perf_thread)); | |
346 | if (!perf_thread) | |
347 | abort(); | |
348 | CDS_INIT_LIST_HEAD(&perf_thread->rcu_field_list); | |
349 | ret = pthread_setspecific(perf_counter_key, perf_thread); | |
350 | if (ret) | |
351 | abort(); | |
352 | skip: | |
353 | ret = pthread_sigmask(SIG_SETMASK, &oldmask, NULL); | |
354 | if (ret) | |
355 | abort(); | |
356 | return perf_thread; | |
357 | } | |
358 | ||
359 | static | |
360 | struct lttng_perf_counter_thread_field * | |
361 | add_thread_field(struct lttng_perf_counter_field *perf_field, | |
362 | struct lttng_perf_counter_thread *perf_thread) | |
363 | { | |
364 | struct lttng_perf_counter_thread_field *thread_field; | |
365 | sigset_t newmask, oldmask; | |
366 | int ret; | |
367 | ||
368 | ret = sigfillset(&newmask); | |
369 | if (ret) | |
370 | abort(); | |
371 | ret = pthread_sigmask(SIG_BLOCK, &newmask, &oldmask); | |
372 | if (ret) | |
373 | abort(); | |
374 | /* Check again with signals disabled */ | |
375 | cds_list_for_each_entry_rcu(thread_field, &perf_thread->rcu_field_list, | |
376 | rcu_field_node) { | |
377 | if (thread_field->field == perf_field) | |
378 | goto skip; | |
379 | } | |
380 | thread_field = zmalloc(sizeof(*thread_field)); | |
381 | if (!thread_field) | |
382 | abort(); | |
383 | thread_field->field = perf_field; | |
b9389e6e JD |
384 | thread_field->fd = open_perf_fd(&perf_field->attr); |
385 | if (thread_field->fd >= 0) | |
77d7fa98 | 386 | setup_perf(thread_field); |
b9389e6e JD |
387 | /* |
388 | * Note: thread_field->pc can be NULL if setup_perf() fails. | |
389 | * Also, thread_field->fd can be -1 if open_perf_fd() fails. | |
390 | */ | |
20142124 | 391 | lttng_perf_lock(); |
d58d1454 MD |
392 | cds_list_add_rcu(&thread_field->rcu_field_node, |
393 | &perf_thread->rcu_field_list); | |
394 | cds_list_add(&thread_field->thread_field_node, | |
395 | &perf_field->thread_field_list); | |
20142124 | 396 | lttng_perf_unlock(); |
d58d1454 MD |
397 | skip: |
398 | ret = pthread_sigmask(SIG_SETMASK, &oldmask, NULL); | |
399 | if (ret) | |
400 | abort(); | |
401 | return thread_field; | |
402 | } | |
403 | ||
404 | static | |
405 | struct lttng_perf_counter_thread_field * | |
406 | get_thread_field(struct lttng_perf_counter_field *field) | |
407 | { | |
408 | struct lttng_perf_counter_thread *perf_thread; | |
409 | struct lttng_perf_counter_thread_field *thread_field; | |
410 | ||
411 | perf_thread = pthread_getspecific(perf_counter_key); | |
412 | if (!perf_thread) | |
413 | perf_thread = alloc_perf_counter_thread(); | |
414 | cds_list_for_each_entry_rcu(thread_field, &perf_thread->rcu_field_list, | |
415 | rcu_field_node) { | |
416 | if (thread_field->field == field) | |
417 | return thread_field; | |
418 | } | |
419 | /* perf_counter_thread_field not found, need to add one */ | |
420 | return add_thread_field(field, perf_thread); | |
421 | } | |
422 | ||
423 | static | |
424 | uint64_t wrapper_perf_counter_read(struct lttng_ctx_field *field) | |
425 | { | |
426 | struct lttng_perf_counter_field *perf_field; | |
427 | struct lttng_perf_counter_thread_field *perf_thread_field; | |
428 | ||
429 | perf_field = field->u.perf_counter; | |
430 | perf_thread_field = get_thread_field(perf_field); | |
a3a8d943 | 431 | return arch_read_perf_counter(perf_thread_field); |
d58d1454 MD |
432 | } |
433 | ||
434 | static | |
435 | void perf_counter_record(struct lttng_ctx_field *field, | |
436 | struct lttng_ust_lib_ring_buffer_ctx *ctx, | |
437 | struct lttng_channel *chan) | |
438 | { | |
439 | uint64_t value; | |
440 | ||
441 | value = wrapper_perf_counter_read(field); | |
442 | lib_ring_buffer_align_ctx(ctx, lttng_alignof(value)); | |
443 | chan->ops->event_write(ctx, &value, sizeof(value)); | |
444 | } | |
445 | ||
446 | static | |
447 | void perf_counter_get_value(struct lttng_ctx_field *field, | |
53569322 | 448 | struct lttng_ctx_value *value) |
d58d1454 | 449 | { |
6e9ac4ae | 450 | value->u.s64 = wrapper_perf_counter_read(field); |
d58d1454 MD |
451 | } |
452 | ||
20142124 | 453 | /* Called with perf lock held */ |
d58d1454 MD |
454 | static |
455 | void lttng_destroy_perf_thread_field( | |
456 | struct lttng_perf_counter_thread_field *thread_field) | |
457 | { | |
b9389e6e | 458 | close_perf_fd(thread_field->fd); |
d58d1454 MD |
459 | unmap_perf_page(thread_field->pc); |
460 | cds_list_del_rcu(&thread_field->rcu_field_node); | |
461 | cds_list_del(&thread_field->thread_field_node); | |
462 | free(thread_field); | |
463 | } | |
464 | ||
465 | static | |
466 | void lttng_destroy_perf_thread_key(void *_key) | |
467 | { | |
468 | struct lttng_perf_counter_thread *perf_thread = _key; | |
469 | struct lttng_perf_counter_thread_field *pos, *p; | |
470 | ||
20142124 | 471 | lttng_perf_lock(); |
d58d1454 MD |
472 | cds_list_for_each_entry_safe(pos, p, &perf_thread->rcu_field_list, |
473 | rcu_field_node) | |
474 | lttng_destroy_perf_thread_field(pos); | |
20142124 | 475 | lttng_perf_unlock(); |
d58d1454 MD |
476 | free(perf_thread); |
477 | } | |
478 | ||
479 | /* Called with UST lock held */ | |
480 | static | |
481 | void lttng_destroy_perf_counter_field(struct lttng_ctx_field *field) | |
482 | { | |
483 | struct lttng_perf_counter_field *perf_field; | |
484 | struct lttng_perf_counter_thread_field *pos, *p; | |
485 | ||
486 | free((char *) field->event_field.name); | |
487 | perf_field = field->u.perf_counter; | |
488 | /* | |
489 | * This put is performed when no threads can concurrently | |
490 | * perform a "get" concurrently, thanks to urcu-bp grace | |
20142124 MD |
491 | * period. Holding the lttng perf lock protects against |
492 | * concurrent modification of the per-thread thread field | |
493 | * list. | |
d58d1454 | 494 | */ |
20142124 | 495 | lttng_perf_lock(); |
d58d1454 MD |
496 | cds_list_for_each_entry_safe(pos, p, &perf_field->thread_field_list, |
497 | thread_field_node) | |
498 | lttng_destroy_perf_thread_field(pos); | |
20142124 | 499 | lttng_perf_unlock(); |
d58d1454 MD |
500 | free(perf_field); |
501 | } | |
502 | ||
d286ad50 JD |
503 | #ifdef __ARM_ARCH_7A__ |
504 | ||
505 | static | |
506 | int perf_get_exclude_kernel(void) | |
507 | { | |
508 | return 0; | |
509 | } | |
510 | ||
511 | #else /* __ARM_ARCH_7A__ */ | |
512 | ||
513 | static | |
514 | int perf_get_exclude_kernel(void) | |
515 | { | |
516 | return 1; | |
517 | } | |
518 | ||
519 | #endif /* __ARM_ARCH_7A__ */ | |
520 | ||
d58d1454 MD |
521 | /* Called with UST lock held */ |
522 | int lttng_add_perf_counter_to_ctx(uint32_t type, | |
523 | uint64_t config, | |
524 | const char *name, | |
525 | struct lttng_ctx **ctx) | |
526 | { | |
527 | struct lttng_ctx_field *field; | |
528 | struct lttng_perf_counter_field *perf_field; | |
d58d1454 MD |
529 | char *name_alloc; |
530 | int ret; | |
531 | ||
532 | name_alloc = strdup(name); | |
533 | if (!name_alloc) { | |
534 | ret = -ENOMEM; | |
535 | goto name_alloc_error; | |
536 | } | |
537 | perf_field = zmalloc(sizeof(*perf_field)); | |
538 | if (!perf_field) { | |
539 | ret = -ENOMEM; | |
540 | goto perf_field_alloc_error; | |
541 | } | |
542 | field = lttng_append_context(ctx); | |
543 | if (!field) { | |
544 | ret = -ENOMEM; | |
545 | goto append_context_error; | |
546 | } | |
547 | if (lttng_find_context(*ctx, name_alloc)) { | |
548 | ret = -EEXIST; | |
549 | goto find_error; | |
550 | } | |
551 | ||
552 | field->destroy = lttng_destroy_perf_counter_field; | |
553 | ||
554 | field->event_field.name = name_alloc; | |
555 | field->event_field.type.atype = atype_integer; | |
556 | field->event_field.type.u.basic.integer.size = | |
557 | sizeof(uint64_t) * CHAR_BIT; | |
558 | field->event_field.type.u.basic.integer.alignment = | |
559 | lttng_alignof(uint64_t) * CHAR_BIT; | |
560 | field->event_field.type.u.basic.integer.signedness = | |
561 | lttng_is_signed_type(uint64_t); | |
562 | field->event_field.type.u.basic.integer.reverse_byte_order = 0; | |
563 | field->event_field.type.u.basic.integer.base = 10; | |
564 | field->event_field.type.u.basic.integer.encoding = lttng_encode_none; | |
565 | field->get_size = perf_counter_get_size; | |
566 | field->record = perf_counter_record; | |
567 | field->get_value = perf_counter_get_value; | |
568 | ||
569 | perf_field->attr.type = type; | |
570 | perf_field->attr.config = config; | |
d286ad50 | 571 | perf_field->attr.exclude_kernel = perf_get_exclude_kernel(); |
d58d1454 MD |
572 | CDS_INIT_LIST_HEAD(&perf_field->thread_field_list); |
573 | field->u.perf_counter = perf_field; | |
574 | ||
575 | /* Ensure that this perf counter can be used in this process. */ | |
b9389e6e JD |
576 | ret = open_perf_fd(&perf_field->attr); |
577 | if (ret < 0) { | |
d58d1454 MD |
578 | ret = -ENODEV; |
579 | goto setup_error; | |
580 | } | |
b9389e6e | 581 | close_perf_fd(ret); |
d58d1454 MD |
582 | |
583 | /* | |
584 | * Contexts can only be added before tracing is started, so we | |
585 | * don't have to synchronize against concurrent threads using | |
586 | * the field here. | |
587 | */ | |
588 | ||
b2cc986a | 589 | lttng_context_update(*ctx); |
d58d1454 MD |
590 | return 0; |
591 | ||
592 | setup_error: | |
593 | find_error: | |
594 | lttng_remove_context_field(ctx, field); | |
595 | append_context_error: | |
596 | free(perf_field); | |
597 | perf_field_alloc_error: | |
598 | free(name_alloc); | |
599 | name_alloc_error: | |
600 | return ret; | |
601 | } | |
602 | ||
603 | int lttng_perf_counter_init(void) | |
604 | { | |
605 | int ret; | |
606 | ||
607 | ret = pthread_key_create(&perf_counter_key, | |
608 | lttng_destroy_perf_thread_key); | |
609 | if (ret) | |
610 | ret = -ret; | |
611 | return ret; | |
612 | } | |
613 | ||
614 | void lttng_perf_counter_exit(void) | |
615 | { | |
616 | int ret; | |
617 | ||
618 | ret = pthread_key_delete(perf_counter_key); | |
619 | if (ret) { | |
620 | errno = ret; | |
621 | PERROR("Error in pthread_key_delete"); | |
622 | } | |
623 | } |